This series is designed to make available to a wider readership selected studies drawing on the work of the OECD Directorate for Education. Authorship is usually collective, but principal writers are named. The papers are generally available only in their original language (English or French) with a short summary available in the other.

An epidemic of obesity has been developing in virtually all OECD countries over the last 30 years.
Existing evidence provides strong suggestions that such epidemic has affected certain social groups more
than others. In particular, education appears to be associated with a lower likelihood of obesity, especially
among women. A range of analyses of health survey data from Australia, Canada, England and Korea were
undertaken with the aim of exploring the relationship between education and obesity. The findings of these
analyses show a broadly linear relationship between the number of years spent in full-time education and
the probability of obesity, with most educated individuals displaying lower rates of the condition (the only
exception being men in Korea). This suggests that marginal returns to education, in terms of reduction in
obesity rates, are approximately constant throughout the education spectrum. The findings obtained
confirm that the education gradient in obesity is stronger in women than in men. Differences between
genders are minor in Australia and Canada, more pronounced in England and major in Korea. The causal
nature of the link between education and obesity has not yet been proven with certainty; however, using
data from France we were able to ascertain that the direction of causality appears to run mostly from
education to obesity, as the strength of the association is only minimally affected when accounting for
reduced educational opportunities for those who are obese in young age. Most of the effect of education on
obesity is direct. Small components of the overall effect of education on obesity are mediated by an
improved socio-economic status linked to higher levels of education, and by a higher level of education of
other family members, associated with an individual’s own level of education. The positive effect of
education on obesity is likely to be determined by at least three factors: (a) greater access to health-related
information and improved ability to handle such information; (b) clearer perception of the risks associated
with lifestyle choices; and, (c) improved self-control and consistency of preferences over time. However, it
is not just the absolute level of education achieved by an individual that matters, but also how such level of
education compares with that of the individual’s peers. The higher the individual’s education relative to his
or her peers’, the lower is the probability of the individual being obese.